You get two sets of room data if you have a light source and move into an unlit room. You'll first get the unlit room data (which is not shown in your front end) and the lit room data.
If you have a light source and are in an unlit room and use the 'look' command, you get only the lit room data.
This means you might be able to refresh the room state by 'look'ing for each step you take in a dark area. The area also has to be mapped (manually? no automap? not sure).
Something more robust might involve checking room descriptions for the string "It's pitch dark and you can't see a thing!"
You can use the ;logxml script from ;repository to check or capture more data :)